Earth boring drill



Aug. 9, 1938. c. E. REED EARTH BORING DRILL Original Filed March a, 19s"! rim! 1?. Reed,

Cla

I Patented lug.9,1938 v I 2,126,039 "1 UNITED STATES PATENT OFFICE EARTH BORING nanlr.

Clarence E. Reed, Wichita, Kans., assignor to Chicago Pneumatic Tool (Jompany, New York, N. Y., a corporation of New Jersey Application March 8, 1937, Serial No. 129,724 Renewed June 21, 1938 22 Claims. (Cl. 255-11) The invention concerns earth boring apparatus The roller cutter has surfaces complementary in which a toothed cutter is mounted to rotate to the frusto-conical raceway 2, and to the cyabout a spindle with anti-friction roller bearings lindrical face of the flange 8 to have frictional between said parts. .contact therewith. It also has a raceway com- The invention consists inthe features and plementary to the raceway 3 of the spindle upon 5 combination and arrangement of parts hereinwhich the cylindrical anti-friction rollers in after described and particularly pointed out in run. Further the roller cutter has a complethe appended claims. mentary surface to the cylindrical face of the In the drawing: flange II to have frictional contact therewith. 1 Figure 1 is a view of the invention with the There is also a frusto-conical raceway surface rotary toothed cutter in longitudinal section complementary to the frusto-conical raceway 5 and with the spindle, together with its support of the spindle upon which the frusto-conical rolland the anti-friction roller bearing assembly in ers I! run. Near the apex the frusto-conical rollside elevation. er cutter has a cylindrical bearing surface 'com- Fig. 2 is a view of the spindle and its support, Dl m n ry t th yl ndrical bearing urface 4a 15 the said spindle being shown partly in section. of the reduced diameter end of the spindle, and

In this drawing the spindle unit includes .a having frictional contact with said surface 411 of support indicated generally at. I and a spindle t e sp nd I its ap x p rt n the r ller cutter formed integrally with said support and comhas an inwardly tapered bore portion to have prising a frusto-conical portion 2, a cylindrical frictional engagement with the tapered terminal 20 portion 3 and a reduced diameter end portion 4 face 4b of thesp d e- A he base of the cutter having a frusto-conical portion 5, The frustothe bore has a cylindrical bearing surface which conical portion 2 of the spindle provides a raceflletiohally engages the yl dr cal surface of way for frusto-conical roller bearings 6, the the e Perth!!! 9 0f the Spindle pp e e larger diamet r nd of hi h are i t tis clearance at a between a shoulder of the roller 25 ward-1y from the vertical axis of thedrill indicutter d the inner end face o the cylindrical cated by the line X-X. Consequently th roller bearing Ill so that no end thrust of the frusto-conical surface'2 tapers inwardly towards Cutter W he PO d upon the end face of the the vertical axis of the drill which is likewise cylindrical roller bearings t h s Pelnt. There I t of t frustoleohical bearing rollers The is also clearance at b between the larger diameter 30 Small inner of these fru toon1ca1 mp. inner end faces of the frusto-conical anti-fricfriction bearing rollers 6 have their inner faces 111011 bearing rollers d the p s Wall Of contacting the inclined surface I of a flange 8 the bore of the roller e formed integrally with the spindle. The outer n assembling the parts the anti-friction rolllarger diameter end faces of the frusto-conical em 5 and Ill are Placed in the e ay Z nd 3 36 rollers 6 find a bearing on the inclined surface respectively of the p dle and then the toothed 1' formed by under cutting t shoulder or base roller cutter is placed in position over these antiportion of t spindle indicated t 9 friction roller bearings by a movement outwardly h cylindrical surface 3 of t spindle pro along the spindle axis from the inner terminal 40 vides a raceway for cylindrical anti-friction rollfree end d Sp d This W b n t e '40 ers II]. This cylindrical raceway 3 is defined by raceway S f c s a d h r t o bearing the inner fa e 8a of the flange 3 a d also by faces of the toothed roller cutter into contact the outer face Ila of a flange ii formed intewith the surfaces of the anti-friction rollers and grally with the spindle, The inner face I lb of with the complementary friction surfaces of the the flange II, that is, that face which is nearest pindle The r ll r' cutt r having been thus 45 to the vertical axis of the drlllfis inclined and p d in Position e riction frusto-ceniit is undercut at lie to engage the outer smaller .cal roller bearings i2 are then inserted through diameter end faces of frusto-conical bearing an' opening l3 in the cutter into place between rollers I2 which run upon the frusto-conlcal the complementary raceway surfaces of the raceway 5 which tapers outwardly in respect to spindle and the cutter bore. After these anti- 50 the vertical axis of the drill. Inwardly of the friction rollers areplaced in position, the open-., frusto-conical raceway 5 there is a plain cylining I3 is closed by a plug ll, there being a slight drical face 4a and this joins an inclined face 4b clearance left between the inner end of the plug which is at the inner terminal end of thespindle, and the outer larger diameter inner end face of the said inclined face lb tapering inwardly. the frusto-conical bearing rollers l2: 1

It will be seen from the above that the antifriction frusto-conical roller bearings 6 between the bases of the roller cutter and the spindle will take end thrust of the roller cutter in a direction outwardly from the vertical axis of the drill. Therefore no end thrust of the cutter in said outward direction will be imposed upon the periphery of the cylindrical roller bearings Ill, and therefore there will be no tendency to unduly press the outer faces of the cylindrical rollers upon the shoulder 8a defining the cylindrical raceway of the spindle, nor will there be any tendency for the roller cutter to impose its outward thrust tendency upon the inner face of the cylindrical roller bearing l0 because of the clearance at a.

End thrust of the roller cutter in a direction inwardly towards the vertical axis of the drill indicated at X-X will be absorbed by the antifriction frusto-conical rollers l2 which incline reversely in respect to the frusto-conical antifriction rollers 6, that is to say, the larger ends of the frusto-conical rollers I2 are directed inwardly towards the vertical axis of the drill while the larger diameter ends of the frusto-conical rollers 6 are directed outwardly in respect to the vertical axis of the drill.

In respect to the thrust of the cutter inwardly towards the vertical axis of the drill, which, as above stated, is taken or absorbed by the frustoconical bearing rollers l2 near the free end of the spindle, it will be noticed that thereby the cylindrical anti-friction bearing rollers ID are relieved from end thrust of the cutter upon their peripheries, and hence there will be no tendency for end thrust of the roller cutter to force the anti-friction cylindrical rollers 10 in a direction inwardly towards the vertical axis of the drill, and unduly press the inner end faces of the'rollers Ill upon the shoulder I la which defines the inner limit of the cylindrical raceway 3. One result, therefore, of the use of the two sets of frusto-conical antifriction roller bearings which incline reversely in respect to each other is that the cylindrical roller bearings will be free from end thrust of the roller cutter both outwardly and inwardly, and thus said cylindrical roller bearings will maintain their axial parallelism to each other and to the axis of the spindle and cutter for free rolling.

Aside from this feature, by the arrangement of the two sets of reversely inclined frusto-conical anti-friction bearing rollers end thrusts of the roller cutter both inwardly and outwardly will be providedfor by anti-friction means. It will be noticed from Fig. 2 that the spindle is in one piece with the spindle support.

The frusto roller cutter A has a toothed base portion at an inclination to the toothed apex portion. The axis of the cutter and spindle inclines downwardly and inwardly towards the vertical axis of the drill at substantially 30 to the horizontal.

It is to be understood that the assembly shown in the drawing is to be combined with the bit head of the earth boring drill, the shank la of the spindle support engaging a part of the bit head to be carried thereby.

Itwill be noted that the frusto-conical rollers 6 in the base of the frusto-conical roller cutter have their axis inclined to and intersecting a projection of the spindle axis beyond the free end or inner side of the roller cutter.

The frusto-conical rollers I2 rotatively lock the toothed roller cutter on the spindle.

I claim:

1. An earth boring drill comprising a bit head and a frusto-conical roller cutter unit carried thereby including a spindle having frusto-conical raceway bearing surfaces oppositely inclined to the spindle axis each of said surfaces being defined by a shoulder of larger diameter than the end of said surface which it adjoins, substantially as described.

2. A toothed frusto-conical roller cutter for earth boring drills having frusto-conical roller bearing raceways spaced apart from each other and the surfaces of which incline towards each other the smaller diameter ends of said raceway surfaces thus being directed towards each other.

3. A spindle and support for a frusto-conical roller cutter of an earth boring drill, said spindle having a reduced diameter free end to be enclosed by said frusto-conical roller cutter and having frusto-conical roller bearing raceway surfaces thereon convergent towards each other, the small diameter ends of said surfaces being directed towards each otherand spaced apart substantially as described.

4. A spindle according to claim 3 having a shoulder defining one end of each of said frustoconical surfaces, said shoulder undercutting a plane at right angles to the spindle axis, substantially as described.

5. In a frusto-conical roller cutter organization of an earth boring drill and in combination a roller cutter of frusto-conical form, a support, a spindle, and two sets of tapered roller bearings positioned on raceways between the cutter and the spindle, said tapered roller bearings being on axes inclined to the axis of the spindle axis, the larger ends of the roller bearings of one set being directed inwardly and the larger ends of the roller bearings of the other set being directed outwardly relative to the vertical axis of the drill, substantially as described.

6. In combination in a frusto-conical roller cutter assembly for earth boring drills, a spindle extending inwardly from its support towards the vertical axis of the drill, said spindle having a frusto-conical raceway at its base portion adjacent the support tapering towards the vertical axis of the drill and having at its free end a frusto-conical raceway tapering outwardly in relation to the vertical axis of the drill.

7. In combination in a frusto-conical roller cutter assemblyfor earth boring drills, a spindle extending inwardly from its support towards the vertical axis of the drill, said spindle having a frusto-conical raceway at its base portion adjacent the support tapering towards the vertical axis of the drill and having at its free end a frusto-conical raceway tapering outwardly in relation to the vertical axis of the drill and a cylindrical raceway intermediate the oppositely inclined frusto-conical raceways, substantially as described.

8. In combination in a roller cutter assembly for earth boring drills, a spindle extending inwardly from its support towards the vertical axis of the drill, said spindle having a frusto-conical raceway at its base portion adjacent the support tapering towards the vertical axis of the drill and having at its free end a frusto-conical raceway tapering outwardly in relation to the vertical axis of the drill, said spindle having a cylindrical raceway intermediate the oppositely inclined frust'oconical raceways, a flange on the spindle between each of the frusto-conical raceways and the cylindrical raceway, said flanges having inclined sides forming shoulders for receiving the smaller diameter ends of frusto-conical bearing rollers, and having their opposing sides forming shoulders in planes at right angles to the axis of the spindle for defining the cylindrical raceway, substantially as described.

9. In combinationin a roller cutter organization for earth boring drills, a spindle having adjacent its base a frusto-conical surface tapering towards the vertical axis of the drill and having near its free end a frusto-conical surface tapering outwardly from the vertical axis of the drill, flanges on the spindle defining the raceways at their smaller ends and defining between them a cylindrical raceway, frusto-conical bearing rollers on the tapered raceways inclining in opposite directions, cylindrical bearing rollers in the cylindrical raceway, a roller cutter having surfaces in its bore complementary to the oppositelytapered frusto-conical racewaysurfaces and to the intermediate cylindrical raceway surface, said cutter being free to be moved into po sition onto the spindle and to bear on the peripheries of the frusto-conical rollers in the bases of the cutter and upon the cylindrical anti-friction rollers, and anti-friction rollers of frustoconical form inserted into the raceway near the free end of the spindle through an opening in .the frusto-conical roller cutter with a plug for closing said opening, substantially as described.

10. In combination in a roller cutter and spindle assembly revoluble about the vertical axis of an earth boring drill, a spindle, a roller cutter, cylindrical anti-friction roller bearings between the roller cutter and the spindle, a set of frusto-conica'l roller bearings between the base portion of the roller cutter and the spindle on axes inclining towards the spindle axis and taking end thrust of the roller cutter outwardly from the vertical'axis of the drill and thereby relieving the cylindrical roller bearings from outward end thrust of the roller cutter, a set of of frusto conical roller bearings between the apex portion of the roller cutter and the free end portion of the spindle taking end thrusts of the roller cutter in a direction inwardly towards the vertical axis of the drill, and thereby relieving said cylindrical roller bearings of said inward end thrust, sub stantially as described.

11. A roller cutter assembly comprising a spindle having two frusto-conical raceway surfaces and a cylindrical raceway surface thereon, roller bearings on said surfaces, a roller cutter having complementary raceway surfaces and surrounding said spindle and roller bearings, one set of said roller bearings being positioned rotatively locking said cutter on said spindle.

12. As an article of manufacture, a spindle for an earth boring drill having on its periphery two frusto-conical racewaysurfaces, and a groove positioned between said surfaces.

13. As an article of manufacture, a spindle for an earth boring drill having two frusto-conical peripheral roller bearing raceway surfaces and a rolling bearing peripheral raceway surface, said spindle having a shoulder adjacent said rolling bearing raceway surface.

14. As an article of manufacture, a roller cutter for an earth'boring drillhaving a toothed exterior and a plurality of bearing surfaces within a bore of said cutter comprising two frustoconical roller bearing peripheral surfaces and a rolling bearing raceway peripheral surface,'and one of said surfaces contacting means for rotatively looking'said cutter on a spindle.

15. In combination, a spindle in one piece having an annular groove therein, the bottom of I which provides a cylindrical raceway surface, a

groove near the'base of said spindle, the bottom of whichtapers towards the inner end of the spindle andan annular surface near the inner end of the spindle tapering outwardly in respect to the vertical axis of the drill, said first mentioned groove being located between the groove near the 'base and the tapered surface-,

near the inner end of the spindle.

16. A roller cutter organization for an earth boring drill revoluble about the vertical axis of said drill comprising a spindle, a roller cutter surrounding said spindle, two sets of frustoconical roller bearings between said cutter and spindle, those of one set tapering inwardly and those of the other set tapering outwardly relative to the vertical axis of thedrill, said cutter and spindle having frictional contact between the sets of roller bearings.

17. A roller cutter organization for an earth boring drill comprising a support, a spindle projecting therefrom and having one end free, a

cutter enclosing said spindle, a plurality of sets of frusto-conical bearings between said cutter and spindle, and a set of cylindrical rollers between said cutter and spindle.

18. A roller cutter organization for an earth boring drill comprising a support, a spindle projeoting therefrom and having one end free, a cutter enclosing said spindle, a plurality of sets of frusto-conical bearings between said cutter and spindle, a set of cylindrical rollers between said cutter and spindle, and a frictional bearing surface between said cutter and spindle.

19. In combination in a frusto-conical roller cutter assembly for an earth boring drill, a spindle extending inwardly of a roller cutter, a roller cutter, said spindle having a frusto-conical raceway tapering towards the vertical axis of the drill and also having another frusto-conical raceway tapering outwardly in relation to the vertical axis of the drill, annular frictional bearing surfaces of the cutter contacting said spindle, and frusto-conical roller bearings on said raoeways.

20. In the combination set forth in claim 19, said spindle having a frictional bearing shouldercontacted by the cutter.

21. In. combination in a roller cutter and spindle assembly revoluble about the vertical axis drill and thereby relieving the anti-friction rolling bearings from' outward end thrust of the roller cutter, another set of frusto-conical roller bearings between the roller cutter and thespindle taking end thrusts of the roller cutter in a direction inwardly towards the vertical axis of the drill, and thereby relieving said anti-friction rolling bearings of said inward end thrust.

22. A frusto-conical roller cutter for earth boring drills having a bore open at its base and closed at its apex, said bore having -a frustoconical raceway wall within the base portion of the cutter tapering towards the apex of the cutter, and a second frusto-conical raceway wall within the apex portion of the cutter tapering towards the open base portion of the said cutter, substantially as described.

CLARENCE E. REED. 

